Raizen High School’s rooftop was currently encased in darkness. The individual responsible is the Spirit with the power to control time, Kurumi. With Tohka, Origami, and Mana unable to fight, Shidou remains the only one able to confront Kurumi and her army of clones. However, a very familiar and yet very unusual person suddenly appears right above the rooftop.

Itsuka Sister continues from the last volume where the battle against Kurumi is going on. Things get personal in this light novel where just the appearance of this particular Spirit is enough to drive everyone into chaos. And yet the volume mellows out the harsh gravity of the situation by bringing our cast into swimsuits before concluding in an emotional finish.

The story goes straight to the action as the volume immediately begins with Kotori’s Spirit appearance. The battles, or fights in general, are done using a third person perspective, with emphasis on the added flavor text for the attacks. In some cases, the perspective will switch temporarily to a focused character to show their feelings towards the matter.

After the fight with Kurumi, we are given more information about the events that happened five years ago which included Shidou and Kotori and even Origami. While the cause of the disaster still remains a mystery with the appearance of an unknown being, it does shed some light for Kotori’s dual personality and deepens our understanding of Shidou and Kotori’s relationship.

In the middle part of the light novel, the tone considerably gets lighter by everyone having fun picking swimsuits-to Shidou’s dismay. There are jokes here and there about Tohka and Origami trying to win over Shidou but this portion serves as a lull for the main event.

The water park date is supposed to be like a challenge for Shidou as he’s trying to woo his own sister who’s been operating his dates from the very beginning, but it really doesn’t feel all that serious. It’s pretty well done in terms balancing the harsh situation Shidou’s troubled with and the comedic routines in the park. Date A Live has always had this ability to spin these types of situation and make it feel positive, forgetting whatever harsh events has happened or will happen, which I commend it for. A good example is the outlook by the crew of the Ratatoskr. All of them are disheartened due to the condition their head commander is in, and yet they all are willing to do their best to give Shidou and Kotori the best possible date they could imagine. Sure, their plans almost end up in disaster (for comedic effect) and at some point dismissed, but the intention rings true. As their date goes on, the mood turns very comfortable and natural as it feels like a normal outing between the siblings.

Shidou is in a rough position for this volume because has he has to deal with the fact that his sister is a Spirit. Together with his failed attempt to save Kurumi and Origami’s lingering hatred towards the Spirits, causes confliction within him. Through the volume, he becomes increasingly worried about the state Kotori is in, but as we progress to the end he becomes more relaxed as he acts to what he thinks is the right thing to do.

Kotori is one tough girl to get through, mainly because of her head commander personality. Having Kotori go on a date with her black ribbons also becomes another outlet for a range of jokes, due to her able to differentiate what are Shidou’s intentions and what are Ratatoskr’s intentions. It was unusual seeing a different personality based on the ribbons she was wearing but it gets addressed in this volume.

The quality of illustrations remains the same from the previous installments but there are a number of illustrations that stand out. Firstly, if you can look closely at the cover page for Itsuka Sister, right behind Kotori is a background of a Ferris wheel which I thought was a nice touch, given the setting for the last event at the end. Most of these pictures depict our cast of characters in swimsuits (at least naked in someway), providing the reader some fan-service their favorite character (pardoning Kurumi, I’m sorry) and these are done very well. If I had to showcase one particular drawing, it would be the illustration where Shidou is taking Origami’s temperature. It’s a very sexy and erotic scene, both in illustration and in context, showing off her trembling expression and soft curves. Another picture to show off for display is the Kotori’s Megaldo, using varying shades of black to illustrate both her cannon and the explosion coming out from it.

Itsuka Sister goes out bare with their characters, both in appearance and in development. We are shown more backstory on the events that happened that five years and its aftereffects to the characters involved. With nice transitioning between a happier tone to a much more serious mood, this volume goes beyond the previous ones by taking good care of its characters.